This invention relates to power transmission belts and, more particularly, to a power transmission belt having a body with an inside and an outside and a fabric material applied to at least one of the inside and outside of the body.
It is known to apply fabric material, such as canvas, to a surface of a V-ribbed power transmission belt. As one example, Japanese Laid-Open Patent Publication No. 4-151048 discloses a V-ribbed belt with a body having a compression rubber layer in which a plurality of longitudinally extending ribs are formed. The body further has a cushion rubber layer, within which load carrying cords are embedded, and applied to the compression rubber layer. A machine joined canvas layer is adhered to the back of the cushion rubber layer. The canvas layer is intended to avoid the development of cracks in the lengthwise direction of the body, and is formed by impregnating a plain-woven cloth, consisting of crossing warp and weft yarns, with rubber.
A typical woven cloth used in the above type of belt is commonly formed by mechanical treatment, namely tenter treatment, in which the intersection angle of warp and weft yarns, which initially is at 90xc2x0 in the plain-woven cloth, is changed to 1200. The canvas yarns are spun yarns made of 100% cotton, each with a tensile strength of at least 9N. The yarns are present in an amount of 14 per 10 mm or more in the belt.
The canvas is then dipped in resorcinol-formalin-latex liquid (RFL liquid) and is thereafter impregnated with unvulcanized rubber or immersed in a soaking liquid, in which rubber is dissolved, to improved the adherence of the canvas to the rubber layer to which it is applied.
Generally, friction treating of the canvas to impregnate the canvas with unvulcanized rubber, after the canvas has been dipped in resorcinol-formalin-latex liquid, is relatively time consuming. Further, if the canvas treated in the above manner is applied to the back of a belt to improve the belt""s power transmission capability, rubber dregs may appear thereon. The dregs tend to accumulate on the back surface of the belt, or wherever the fabric material is applied. This may result in noise generation. Another problem is that the rubber dregs may separate and scatter to other products, to equipment used to form the belts, and to other areas in the vicinity of the equipment.
The process in which the fabric material is dipped in a soaking liquid also may take a considerable amount of time to carry out. Even though the rubber content may be less using this process, rubber dregs may still appear on the fabric material.
In one form, the invention is directed to a power transmission belt having a body with a length, an inside, an outside, and laterally oppositely facing side surfaces. The body has a) a cushion rubber layer in which at least one load carrying element is embedded so that the at least one load carrying element extends lengthwise relative to the body and b) a compression rubber layer. Fabric material is provided on one of the inside and outside of the body. The fabric material is treated with a mixture of carbon-black-dispersed liquid and resorcinol-formalin-latex liquid.
In one form, a solid component weight ratio of carbon black to the resorcinol-formalin-latex in the mixture is 1:9 to 7:3.
The mixture may further include a cross-linking agent capable of being dispersed in water.
The cross-linking agent may include a colloidal sulfur. The colloidal sulfur may be present in the mixture in a range of 0.2 to 10 parts by mass per 100 parts of a latex component.
The cross-linking agent may include an organic peroxide. The organic peroxide may be present in the mixture in a range of 0.2 to 15 parts by mass per parts of a latex component.
In one form, the cross-linking agent includes a metal oxide and a latex component in the resorcinol-formalin-latex liquid has functional groups.
In one form, the cross-linking agent includes a zinc oxide and a latex component in the resorcinol-formalin-latex liquid is vinylpyridine latex.
In one form, the cross-linking agent includes a metal oxide. The metal oxide may be present in the mixture in a range of 0.5 to 15 parts by mass per 100 parts of a latex component.
In one form, the carbon black in the carbon-black-dispersed liquid is at least one of HAF, MAF, EPC, and ISAF.
The mixture may further include a vulcanization accelerator. The vulcanization accelerator may be present in an amount of 0.5 to 10 parts by mass per 100 parts by mass of a latex component.
In one form, solid components in the mixture are present in a range of 5-40%.
The compression rubber layer may have at least one rib extending lengthwise of the body. In one form, the at least one rib is on the inside of the body and the fabric material is on at least the outside of the body.
In one form, the fabric material is made from at least one of a) natural fiber, b) inorganic fiber, and c) organic fiber formed by one of i) plain weaving, ii) twill weaving, and iii) sateen weaving.
The body may further include short fibers which have lengths extending generally in a lateral direction.
The power transmission belt may be a V belt with the fabric material on the inside and/or the outside of the body.
The power transmission belt may be a flat belt.
In one form, the compression rubber layer is defined by at least one of a) hydrogenated nitrile rubber, b) chloroprene rubber, c) natural rubber, d) CSM, e) ACSM, f) SBR, and g) ethylene-xcex1-olefin elastomer.
In one form, the at least one load carrying element is a load carrying cord defined by at least one of a) polyester fiber, b) aramid fiber, and c) glass fiber.
The invention is further directed to a power transmission belt having a body with a length, an inside, an outside, and laterally oppositely facing side surfaces. A fabric material is provided on at least one of the inside and outside of the body. The fabric material is treated with a mixture of carbon-black-dispersed liquid and resorcinol-formalin-latex liquid.
The body may further include at least one load carrying element extending lengthwise relative to the body.
The load carrying element may be a load carrying cord.
The power transmission belt may be any of a V-ribbed belt, a V belt, or a flat belt.